Download 2105Lecture 4a powerpoint

Note
Lecture 4a
3 February 2014
Type 1 Diabetes
• Pathology
• Nutritional Intervention-pre- and post-onset
Pathology of Type 1 diabetes-must first discuss the
role of insulin
Insulin
-produced in the beta cells of the pancreas
-initially synthesised as a single chain 86
amino acid (86 mer) polypeptide (called preproinsulin)
-post-translational modification removes the
amino terminal signal peptide
what is a signal peptide?
Role of insulin
-removal of the signal peptide give rise to
proinsulin
-insulin is created via the cleavage of an internal
peptide and the A and B chains of insulin are
then linked together by a disulphide linkage
(enzyme responsible?)
-upon glucose arriving at the pancreas insulin is
secreted into blood
Role of insulin
-upon insulin arriving via the blood at its
cellular receptors it sets up a series of steps that
ultimately lead to glucose being brought inside
the cell
Causes of Type 1 diabetes
•
Genetic-pre-disposition to autoimmune attack
•
Autoimmune-beta cells in pancreas are attacked and destroyed by
one’s own immune system-this attack stops insulin production and
secretion
•
Nitroamines-derived in stomach from nitrogen containing
preservatives in meats (eg hot dogs, baloney)- nitrosamines attack the
pancreatic beta cells-system-this attack stops insulin production and
secretion
•
Casein (milk, cheese, yoghurt)-sets up immune response that attack the
pancreatic beta cells-system-this attack stops insulin production and
secretion
•
Viruses – cocksackie and rubella-system-this attack stops insulin
production and secretion
Dietary management of type 1 diabetes-prevention
• avoid cows’ milk, cream , cheese and yogurt (anything else with
whole casein in it) if under 1 year of age
• avoid nitrosamines to the extent possible-hot dogs and baloney to
give but two examples
• Avoid cocksackie and rubella viruses in food to the extent possible
Dietary management of type 1 diabetes-post-onset
management
• insulin prescription and healthy diet are matched
• largely the same as type 2 diabetes with some points
directed at type 1 diabetes specifically (see nutrition
section at end of lecture 4D today)
Dietary management of type 1 diabetes-postonset
Whole idea with nutrition post-onset is along with
diet and exercise and insulin prescription to meet
target HbA1c, lipids(including cholesterol), blood
pressure goals to attempt to minimise vascular
complications (the major cause of death and
disability in type 1 diabetics)
For exercise see the exercise notes at the end of
lecture 4D today-many similarities between type 1
and type 2 diabetes in terms of exercise